Energy requirement during pregnancy is important to ensure the safe delivery of healthy offspring. It is well established that protein and fat deposition occurs in baby and maternal tissues during pregnancy. However, there are no direct and reliable methods available to measure body composition during pregnancy in order to manage and monitor the energy requirements of pregnant women. The World Health Organization (WHO) has calculated the mean fat accretion which occurs during pregnancy, in the period of up to 36 weeks from gestation, using mainly pre and post pregnancy measurements (Chapter 6—Energy Requirements of Pregnancy, Human Energy Requirements: Report of a Joint FAO/WHO/UNU Expert Consultation Rome, 17-24 Oct. 2001, pp 53-62.). However, this approach suffers from large estimation errors and it is not based on actual measurements taken during the pregnancy.
It is also known that both magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) are considered accurate methods to determine body fat percent in a human subject. However, these approaches are contraindicated during pregnancy because of the health concerns with exposure to a magnetic field or x-rays, respectively.
On the other hand, other known non-invasive or minimally invasive methods such as skin fold or bioimpedence measurements, have not been found to be reliable. Other known methods for determining body fat percent are also not generally desirable for use on pregnant women. These include underwater weighing, air displacement plethysmography, body water dilution technique, and the like. Other approaches to determining body fat percentages, including such as body mass index (BMI), are also typically not appropriate due to inherent inaccuracies.
In U.S. Pat. No. 7,711,411, the contents of which are incorporated herewith, a non-invasive technique to measure body fat percent is described which utilized a Fourier transform near infrared spectroscopy (FT-NIR) technique. The FT-NIR technique is relatively quick and easily conducted, and involves minimal intrusion. In a preferred approach, a fiber optic probe is directed at the back of a subject's ear and then the reflected or transmitted FT-NIR signals are processed, using pre-developed calibration models, to provide the subcutaneous fat percentages of an individual, in minutes. More importantly, the measurements from the FT-NIR technique were found to equate well to other, more traditional tests for body fat percent such as DXA and MRI.
In U.S. Pat. No. 7,039,458, a technique is described for measuring and controlling body fat percent during pregnancy, but this technique relies on the use of bioelectrical impedance. In addition, the described technique requires the user to determine and input various parameters directly into the system, including non-related factor (e.g. the baby's weight) using various other techniques.
Health Canada has published guidelines for weight gain during pregnancy based on the mother's initial BMI (“The Sensible Guide to a Healthy Pregnancy”; Government of Canada, Health Canada, 2008—Revised 2012). These are reproduced below:
BMIRecommended Weight GainBelow 18.512.5 to 18 kg (28 to 40 pounds)Between 18.5 and 24-911.5 to 16 kg (25 to 35 pounds)Between 25.0 and 29.97 to 11.5 kg (15 to 25 pounds)30 and more5 to 9 kg (11 to 20 pounds)
However, these values only provide a guideline for total weight gain during the 9 month pregnancy, and do not describe or advise of any details of the timing of the expected weight gain. Moreover, at the low BMI, and in particular, the high BMI values, the timing of fat accretion can be critical.
It would therefore be desirable to provide a technique for measurement of body fat percent during pregnancy, and thereafter use those measurements to control body fat percent and fat accretion during pregnancy.
It would therefore also be desirable to provide a method for monitoring body fat percent and fat accretion during pregnancy.
Further, it would also be desirable to measure, monitor and control the weight gain of the user, during the various stages of pregnancy, while ensuring the health of the mother and baby by monitoring fat accretion.
These and other advantages, as set out hereinabove, as well as other objects and goals inherent thereto, are at least partially or fully provided by the body fat percent measurement technique of the present invention, particularly when used in conjunction with fat gained, and weight gain measurements, as set out herein below.